Deaf or hearing impaired people often use specialized equipment to communicate over telephone lines. This equipment involves a keyboard and display and is usually called a TeleTypewriter (TTY) or Telecommunication Device for the Deaf (TDD). To the extent necessary in this application, the term TTY will be used, as it appears the most used, and most acceptable.
Telephone service providers or carriers offer telecommunications relay services (TRS) that are used to in connection with the TTY devices. TRS provides transmission services that enable an individual who has a hearing impairment or speech impairment to engage in communication in a manner that is functionally equivalent to the communication of those without an impairment. So TRS allows the communication of alphanumeric information over phone lines. In this way, hearing impaired people can communicate in a text-based conversation over the phone lines. While internet-based chat or messaging has become more common, the use of the TTY devices, and TRS, remains widespread The National Exchange Carrier Association (NECA) administers the Telecommunications Relay Services Fund, and collects from various companies based on interstate revenues. NECA then disburses the collected funds to providers of interstate TRS. So there is financial incentive to provide interstate TRS services.
However, service providers may have to comply with both state and federal regulations related to TRS and these regulations may change over time. As these regulations change, providers of TRS are faced with decisions of whether to increase capital expenditures on equipment needed to comply with the new regulations or whether to maintain legacy equipment that has been used previously.
Certain of the new regulations call for signaling to be signaling system 7 (SS7) based, and to allow callers to choose a long distance carrier for their calls. To provide SS7 signaling in a legacy system, an inventor of this application also invented and developed a message conversion system, shown and described in U.S. patent application Ser. No. 10/773,066, filed on Feb. 5, 2004 entitled Message Conversion System, the contents of which are hereby incorporated by reference. Prior to the message conversion system solution, an automatic call distributor (ACD) was used to route calls to an agent that provided service for the call. The ACD associated with TRS would previously have utilized a time-division multiplexed (TDM) communication link between the ACD and a switch on the long distance network. This scenario would not comply with the new requirements for TRS. The solution proposed by the message conversion system includes a message converter associated with the ACD that takes traditional in-band signaling and converts it to the required SS7 output.
A system is thus still needed that can provide SS7 signaling in connection with TRS and that allows carrier of choice. A system is also needed that can employ a relatively low cost method of providing TRS with both SS7 signaling and that allows carrier of choice selection.